Issue
EPL
Volume 87, Number 6, September 2009
Article Number 66004
Number of page(s) 5
Section Condensed Matter: Structural, Mechanical and Thermal Properties
DOI http://dx.doi.org/10.1209/0295-5075/87/66004
Published online 12 October 2009
EPL, 87 (2009) 66004
DOI: 10.1209/0295-5075/87/66004

Crack front propagation by kink formation

F. Rösch and H.-R. Trebin

Institut für Theoretische und Angewandte Physik, Universität Stuttgart Pfaffenwaldring 57, 70550 Stuttgart, Germany, EU

frohmut.roesch@itap.physik.uni-stuttgart.de

received 21 July 2009; accepted in final form 14 September 2009; published September 2009
published online 12 October 2009

Abstract
The fracture of a three-dimensional brittle solid generates two-dimensional surfaces, which are formed behind a one-dimensional crack front. For quasi-static cracks on a (111) cleavage plane in silicon front propagation by kink-pair formation was proposed and proven by a reaction pathway analysis with Stillinger-Weber potentials. Here, we demonstrate that the kink-pair mechanism is much more general: we also observe it in molecular-dynamics simulations of a complex metallic alloy, the C15 NbCr2 Friauf-Laves phase, where we applied carefully selected embedded-atom-method potentials. The numerical experiments highlight that kink formation is essential for crack propagation in any brittle material.

PACS
62.20.mj - Brittleness.
61.72.-y - Defects and impurities in crystals; microstructure.
02.70.Ns - Molecular dynamics and particle methods.

© EPLA 2009